02-18-2016, 06:42 PM
Putting aside Hollywood movies, both Matt and Paul make valid points. If an asteroid with our name on it is discovered, then the more time we have the better chance we have to deal with it. Whether that's blowing it up or deflecting it will likely depend on what the asteroid is made of. Is it a loose collection of rubble or a dense lump of metal and rock? That's where ground-based telescopes come into play. Although we have telescopes that detect near-earth asteroids (NEOs, or near Earth objects), the most they can do is detect them and allow us to calculate their orbit.
The field is changing though. For instance, UKIRT is now being used by NASA to help understand the structure and composition of those asteroids as it has a unique suite of instruments that allow this. The TMT would allow even better measurements, possibly even including the NEO's shape, pretty critical if you intend to blow it up or deflect it. Doing this by launching a probe would take years of development, not helpful if time is critical.
We have also launched a couple of missions in recent years to study asteroids and comets, e.g., Deep Impact and Philae/Rosetta. One benefit from these missions is to gain experience on how to land something on a comet or asteroid, something likely needed if we want to deflect a NEO. However, even those missions depended on ground-based telescopes supporting them.
As for Matt's comment about the technology already existing, well, I'm not sure it's as simple as that. Some of it does, some of it probably doesn't, but given a threat to the planet I'm sure there would be a rush to develop what's needed, but it would still need the observations of ground-based telescopes such as the TMT to make it happen.
The field is changing though. For instance, UKIRT is now being used by NASA to help understand the structure and composition of those asteroids as it has a unique suite of instruments that allow this. The TMT would allow even better measurements, possibly even including the NEO's shape, pretty critical if you intend to blow it up or deflect it. Doing this by launching a probe would take years of development, not helpful if time is critical.
We have also launched a couple of missions in recent years to study asteroids and comets, e.g., Deep Impact and Philae/Rosetta. One benefit from these missions is to gain experience on how to land something on a comet or asteroid, something likely needed if we want to deflect a NEO. However, even those missions depended on ground-based telescopes supporting them.
As for Matt's comment about the technology already existing, well, I'm not sure it's as simple as that. Some of it does, some of it probably doesn't, but given a threat to the planet I'm sure there would be a rush to develop what's needed, but it would still need the observations of ground-based telescopes such as the TMT to make it happen.